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Abstract:

An embodiment of the invention provides a location based service (LBS)
that updates a first version of information provided a mobile terminal
responsive to a geo-query relative to a second, later version of
information responsive to the geo-query by transmitting portions of the
second version to the mobile terminal rather than all of the second
version.

Claims:

1. A method of providing location based information to a mobile terminal,
the method comprising: receiving a geo-query from a mobile terminal at a
first time; transmitting a first version of information responsive to the
geo-query to the mobile terminal; receiving the geo-query a second time;
determining a difference between information from the first version that
is retained by the mobile terminal at the second time and a second
version of information responsive to the geo-query at the second time;
and transmitting a response to the mobile terminal that includes only a
part of the second version that is responsive to the difference and
useable to update the retained information so that the updated
information is substantially the same as the second version information.

2. A method according to claim 1 and comprising generating a first ETag
to label the first version of the information and a second ETag to label
the second version of the information

3. A method according to claim 2 and comprising determining that there is
a difference between the first and second versions if there is a
difference between the first and second ETags,

4. A method according to claim 3 and comprising determining the
difference responsive to the ETags.

5. A method according to claim 4 wherein determining the difference
comprises determining portions of the retained information and the second
information that differ.

6. A method according to claim 3 and comprising receiving information
relevant to the retained information from the mobile terminal and
determining the difference responsive to the received relevant
information.

7. A method according to claim 6 wherein the relevant information
comprises ETags identifying portions of the retained information.

8. A method according to claim 1 wherein the geo-query at the first time
requests information for a first geographically limited region in which
the mobile terminal is currently located.

9. A method according to claim 8 and determining the geographically
limited region responsive to a range measured from the current location
of the mobile terminal.

10. A method according to claim 9 wherein the range sets an upper limit
to a distance from the current location for which the first information
provides information.

11. A method according to claim 9 wherein the range is a function of
direction from the current location.

12. A method according to claim 1 wherein the geo-query at the first time
requests information for a first geographically limited region in which
the mobile terminal is not currently located.

13. A method according to claim 12 wherein the mobile terminal is in
motion and comprising determining the first geographically limited region
as a region that includes an expected future location of the mobile
terminal responsive to the motion.

14. A method according to claim 8 wherein the first information provides
information associated with venues located in the first geographically
limited region.

15. A method according to claim 14 wherein the first version information
provides information associated with venues in a geographically limited
region larger than, and at least partially overlapping with the first
limited geographical limited region.

16. A method according to claim 15 and determining a size of the larger
geographically limited region responsive to an amount of information
transmitted to the mobile terminal.

17. A method according to claim 8 wherein the second version information
provides information associated with venues in a second geographically
limited region that at least partially overlaps the first geographically
limited region.

18. A location base service (LBS) comprising at least one processor
programmed with a computer executable instruction set executable to
implement a method according to any of the preceding claims.

19. An LBS according to claim 18 wherein the at least one processor
includes a processor in a mobile terminal and a processor comprised in at
least one server.

Description:

TECHNICAL FIELD

[0001] Embodiments of the invention relate to providing location based
service (LBS) information to mobile communication terminals.

BACKGROUND

[0002] Present day communication systems support a rich menu of different
voice, video, text and data communication services between mobile and
stationary communication terminals and the people who use them. In
addition, they support internet connectivity and a growing variety of
location based services (LBSs). An LBS provides a person with
information, entertainment and/or communications via an audio and/or
visual interface of a mobile terminal which the person is using and
carrying, responsive to a current geographical location of the person.
The mobile terminal may be any of today's ubiquitous portable
communication accessories, such as for example, a smart phone, a personal
digital assistant (PDA), a laptop, or a workbook. Unless specified
otherwise, information is understood to be used generically to include
information, entertainment, and/or data that may be provided by an LBS.

[0003] The person's geographical location is typically determined from a
location provided by any of various wireless location technologies of the
mobile terminal. The location technologies include, by way of example,
those employed by global navigation satellite systems, such as the global
positioning satellite (GPS) system, mobile telephone networks, and/or
Wi-Fi and may be automatic and/or require performance of a check-in
procedure by the person.

[0004] Relevant LBS information provided or available to a person from a
LBS via his or her mobile terminal may comprise information regarding
manmade and/or natural features, hereinafter also referred to as venues,
of an environment, which are, generally, within a limited geographical
region and that he or she can physically access within a relatively short
term period of time. Venues provided by the LBS, may, also be for a
geographical region in which a person is not currently present but for
which the person is interested in receiving information independent of
distance of the geographical region from the person's current location.
Relevant information provided to a person by his or her LBS may also
comprise information regarding locations of other persons, which
locations may or may not be accessible within a short period of time by
the person requesting the information.

[0005] Typically, the information is provided by a server in a
communication network in response to requests that the network receives
from the person and in response to communications that the network
receives which provide the person's location. The requested information
may, by way of example, be for a local road map, with or without visual
and/or audio aids for using the map to drive from the person's current
location to a desired destination, or for locations of restaurants,
stores, theaters and/or other desired venues within walking or driving
range of the person. The information may also comprise alerts, and/or
reminders, for example, to acquire or redeem coupons, or to attend to
desired errands at particular venues within a predetermined distance from
the person's current location. Requests for information relevant to a
geographical location transmitted to an LBS are also referred to
hereinafter as "geo-queries".

[0006] The relevant information is, by definition, location dependent and
is of course subject to change as the person moves and changes his or her
location. Relevant information may also be time dependent and change, or
become "stale", with time of day, or as the environment in which the
person is located changes over time. For example, information regarding
an opportunity to purchase tickets to a given showing of a movie at a
theater within walking distance of a person may change and become
obsolete if at a time at which showing the movie begins, the opportunity
lapses. Or, information indicating that a miniature golf range is open
may change if upon onset of a summer rain squall, the golf range closes
to visitors. The information may also change as needs and preferences of
a person change. For example, a person who geo-queried an LBS to provide
addresses for two sidewalk Italian restaurants nearest to her current
location may, if it begins to rain, determine that she can delay the
Italian restaurant and submit an urgent priority request for a location
of a nearest store that sells umbrellas.

[0007] To provide an acceptable quality of service in response to a
client's geo-queries, an LBS typically transmits amounts of information
to a mobile terminal, such as a smart phone, that may be comparatively
very large relative to the device's memory and information processing
resources. The amount of information may also be large relative to a
communication bandwidth that the device supports for receiving the
information. In addition, determining the device's geographical location
using GPS signals, or signals from a mobile telephone network is energy
intensive. Repeatedly updating the LBS with the device's geographical
location can draw down the device's battery relatively quickly. Repeated
location updating and geo-querying may also be relatively expensive.

SUMMARY

[0008] An aspect of an embodiment of the invention relates to providing a
relatively efficient method of providing and updating location based
information to a client mobile terminal and providing an LBS that uses
the method. The method is relatively conservative in its use of
bandwidth, and/or consumption of client energy, and/or use of client
memory, and/or information processing resources. In the discussion that
follows reference to a client is understood to refer to a mobile terminal
or to a person operating the mobile terminal. For example, reference to
client energy, memory, processing resource, or reception or transmission
of information may appropriately refer to a feature or activity of the
client's mobile terminal or to an activity of a person operating or
mediated by the mobile terminal.

[0009] According to an embodiment of the invention, a response that an LBS
provides a client comprising information to answer a geo-query is
associated with a plurality of variables that characterize the response
and information included in the response. The variables may conveniently
be thought of as components of a response identity "vector", hereinafter
referred to as a "Response-ID". The components are used to manage
communications between the client and the LBS to moderate bandwidth that
a communications network allocates to support the communications, and/or
energy consumed in acquiring geographic locations for the client, and/or
appropriation of client memory, and/or processing resource. In an
embodiment of the invention, the components optionally comprise an entity
tag, referred to as an, "ETag", a list of at least one geographic "Tile
ID", a "Tarry Time", an "Expiration Date", and a "Range". A component of
the Response-ID may be determined by the client, optionally in a
geo-query, and/or by the LBS responding to a geo-query. The Response-ID
may be comprised in a header or data payload of a packet or packets
transmitted to the client from a server in the network to deliver
information in the response.

[0010] The ETag component of the Response-ID is determined as a function
of the information included in the response transmitted to the client and
operates as an identifier or label that "fingerprints" the information as
a particular version of the information. A version of the information
that differs in any way from the particular version transmitted to the
client is labeled in accordance with an embodiment of the invention with
a different ETag.

[0011] ETags in accordance with an embodiment of the invention are used to
determine if there is a difference between information provided a client
in a first response to a given geo-query from information available to
the LBS to provide a second response to a later submission by the client
of substantially the same given geo-query. If the ETags for the first and
second responses are different, and the information in the first response
is stored in the client memory, in the second response the LBS may
provide the client with substantially only information needed to update
the stored information. Upon updating the stored information, the client
assigns the second ETag to the updated version of the information.
Transmitting information in the second response to the client that is
usable to update the stored information rather than transmitting all the
information reduces bandwidth used in responding to the second geo-query.

[0012] The "Tile ID List" component of the Response-ID lists at least one
code, a Tile ID, identifying a geographic tile defined by a border that
designates a location and spatial extent of a specific geographical
region associated with the information in the response to the client. In
accordance with an embodiment of the invention, the LBS uses Tile IDs as
indices to monitor and configure location, size and resolution of tiles
associated with information that the LBS provides the client to moderate
an amount of the information or a frequency with which it is provided.

[0013] The Tarry Time component of the Response-ID defines a period of
time for which the information included in the response by the LBS is
considered to be of sufficient relevance to be stored and to remain
stored in client memory.

[0014] The Expiration Date component of the Response-ID defines a date and
a time at which validity of information provided by the LBS in a response
to a given geo-query by the client and stored in client memory, is
considered to expire and should be revalidated to determine if it is
currently accurate. In accordance with an embodiment of the invention,
the ETag associated with the information to be revalidated is checked
against an ETag associated with information currently available to the
LBS, usually substantially at the expiration date, to respond to the same
given geo-query. If the ETags are the same, the information is
revalidated. If the ETags are not the same, the LBS sends the client
information needed to update the stored information rather than a
complete updated copy of the stored information.

[0015] The Range component of the Response-ID optionally provides a
maximum distance between a current location of the client and the
location of a tile identified by the Tile ID List component of the
Response-ID for which the information in the response associated with the
tile is considered relevant. In an embodiment of the invention, Range may
be a function of direction. For example, range may be larger in a
direction in which a client is moving and smaller in a direction opposite
to the client's direction of motion. Information determined to be
irrelevant because it is "out of range" is deleted from, or not stored,
in client memory.

[0016] In the discussion, unless otherwise stated, adjectives such as
"substantially" and "about" modifying a condition or relationship
characteristic of a feature or features of an embodiment of the
invention, are understood to mean that the condition or characteristic is
defined to within tolerances that are acceptable for operation of the
embodiment for an application for which it is intended.

[0017] This Summary is provided to introduce a selection of concepts in a
simplified form that are further described below in the Detailed
Description. This Summary is not intended to identify key features or
essential features of the claimed subject matter, nor is it intended to
be used to limit the scope of the claimed subject matter.

BRIEF DESCRIPTION OF FIGURES

[0018] Non-limiting examples of embodiments of the invention are described
below with reference to figures attached hereto that are listed following
this paragraph. Identical structures, elements or parts that appear in
more than one figure are generally labeled with a same numeral in all the
figures in which they appear. Dimensions of components and features shown
in the figures are chosen for convenience and clarity of presentation and
are not necessarily shown to scale.

[0019] FIG. 1 schematically shows a Response-ID that characterizes a
response to a geo-query that an LBS provides a client in accordance with
an embodiment of the invention; and

[0020] FIG. 2. Schematically shows a map of a region through which a
person travels and for which the person receives information responsive
to geo-queries that she submits to an LBS, in accordance with an
embodiment of the invention.

DETAILED DESCRIPTION

[0021] In the following detailed description, a Response-ID vector in
accordance with an embodiment of the invention is schematically shown in
FIG. 1. Aspects of components of the vector and their uses are discussed
with reference to the figure. FIG. 2 schematically shows a person
traveling to a vacation spot. Use of components of Response-ID vectors
similar to that shown in FIG. 1 to provide the person with LBS
information during the person's trip, and upon the person reaching the
vacation spot, are discussed with reference to the figure.

[0022] FIG. 1 schematically shows a Response-ID vector 20 in a form of a
column vector having optionally five components 30, 40, 50, 60, and 70,
respectively an ETag, a Tile ID List, a Tarry Time, an Expiration Date,
and a Range. The Response-ID characterizes information in a response by
an LBS to a given geo-query submitted by a client to the LBS, in
accordance with an embodiment of the invention.

[0023] ETag component 30 of Response-ID 20 labels information provided by
the LBS at a given first time in response to the geo-query as a
particular version of the information. The ETag optionally comprises a
string of data determined using any of various coding algorithms. An ETag
in accordance with an embodiment of the invention may for example be
determined similarly to the way in which error correcting codes are
determined in telecommunications and information theory. Optionally an
ETag comprises a concatenation of select bits from a data string
representing the information transmitted to the client. Optionally an
ETag comprises a date stamp that labels a date at which the information
was assembled.

[0024] If the information available to the LBS to answer the same
geo-query by the same client at a second time later than the first time
is changed in any way relative to the particular version of the
information transmitted in the response at the first time, the changed
information is considered a new version of the information. The new
version is assigned a new ETag different from the ETag labeling the
version of the information transmitted at the first time.

[0025] In FIG. 1 A list 31 shown in an inset 36 and comprising, venue-1,
venue-2 . . . venue-N, labeled with, an optionally binary, ETag 32, is
assumed by way of example to be the information provided to the client by
the LBS at the first time in response to the client's given geo-query.
The list, together with its ETag 32, is assumed to be stored in the
client memory (not shown). At a later, second time, a list 33 comprising
venue-2, venue-4 . . . venue-N is available to the LBS to respond to the
same geo-query by the same client. List 33 is changed with respect to
list 31 and is missing venue-1 and venue-3. List 33 is therefore labeled
with an, optionally binary ETag 34 different from ETag 32.

[0026] In an embodiment, if at the second time the client attempts to
access stored list 31 or submits the given geo-query to the LBS again,
the client transmits the geo-query and ETag 32 to the LBS. The LBS
compares ETag 32 to ETag 34, and determines that they are different and
that therefore list 31 stored in the client memory is not up to date. To
provide up to date information to the client, in accordance with an
embodiment, the LBS determines a difference between list 31 and list 32
and transmits to the client information defining the determined
difference rather than transmitting all of list 33 as a replacement for
list 31. The difference, which in the current example is the absence of
venue-1 and venue-3 in list 33, enables the client to amend stored list
31 so that it is identical to list 33. Upon updating stored list 31, the
client assigns ETag 34 as the ETag for the stored list. Transmitting
substantially only updating information to the client rather than all of
list 33 reduces communication bandwidth used to provide the client with
an updated response to the given geo-query.

[0027] In an embodiment of the invention, the LBS determines a difference
between "first" information responsive to a geo-query, which is
transmitted to a client at a first time, and "second" information
available for transmission to the client at a second time by requesting
information from the client sufficient to determine the difference. For
example, in an embodiment of the invention, information defining each
venue provided to a client in response to a geo-query may itself be
labeled by an ETag. To determine a difference between the first
information that the client has and the second information available at
the LBS, the LBS may request a list of the venue ETags in the first
information and compare it to venue ETags in the second information. A
difference in the ETags associated with the first information and the
ETags associated with the second information indicate a difference
between the first and second information.

[0028] Optionally, if information provided clients of the LBS is labeled
with error correcting type ETags that are calculated similarly to a
manner in which error correcting codes in telecommunication applications
are calculated, a comparison of a first ETag labeling first information
with a second ETag labeling second information may be sufficient to
define a difference between the first information and the second
information. For example, error correcting ETags in accordance with an
embodiment of the invention, may be used to determine where first and
second strings of data representing respectively the first information
and the second information differ. The LBS may update the first
information by transmitting to the client information sufficient to
modify that portion of the first string that differs from the second
string so that the two strings are identical rather than by transmitting
all of the second string to the client.

[0029] Tile ID List, component 40, lists at least one Tile ID that
identifies a particular tile or a plurality of particular tiles comprised
in a grid of, optionally nested tiles, which segment a large extended
geographical area into different, adjacent geographical regions. Each
tile in the grid is defined by a border that designates a location and
spatial extent of a specific geographical region in the extended
geographical area and is associated with information that relates to
and/or locates natural and/or manmade features within the region
designated by the tile's border. The tile is characterized by a spatial
resolution at which details of the features are represented by
information associated with the tile. In an embodiment, each nested tile
has a spatial resolution greater than a tile in which it is directly
nested by a factor equal to a ratio of the area of the nesting tile
divided by the area of the nested tile.

[0030] The at least one Tile ID in the Tile ID List in Response-ID 20
indicates that information provided in the response provided by the LBS
is associated with the geographical region or regions identified by the
at least one Tile ID in the Tile ID List. The information in the response
is configured responsive to the spatial resolution with which features in
the geographical region are represented by information associated with
the at least one tile identified in the Tile ID List.

[0031] Optionally, the grid of tiles comprises a Bing Maps Tile System
(BMTS) in which each tile is square, and except for a smallest tile is
partitioned into four nested tiles. Each given tile is designated by an
integer number Tile ID referred to as a "Quadkey". The four nested tiles
that partition a given tile are each designated by the integer number
Quadkey of the nesting tile plus a numeral 0, 1, 2 or 3 respectively
added as a least significant digit to the Quadkey of the nesting tile.
The additional least significant numeral in the order, 0, 1, 3, or 2, is
added to the nesting tile Quadkey to respectively designate a given
nested tile in clockwise order of the position of the nested tile being
designated starting from the upper left corner of the nesting tile. By
way of example, an inset 41 schematically shows a Bing tile 113 nesting
tiles identified by Quadkeys 1130, 1131, 1132, and 1133. Tile 1132 is
shown partitioned into nested tiles identified by Quadkeys 11320, 11321,
11322, and 11323.

[0032] In an embodiment of the invention, information provided to the
client by the LBS in response to a geo-query is determined on a basis of
the client's current need to know, and/or an anticipated need to know.
Current need to know information comprises information provided by the
LBS in response to the geo-query that is associated with at least one
"occupied" or "unoccupied" tile, which has a size and resolution
appropriate for providing the information. An occupied tile is a tile in
which the client is currently physically present. An unoccupied tile
associated with a geo-query is a tile, in which the client is not
currently physically present, but which the client specifically
identifies in the geo-query and for which the client requests
information. Anticipated need to know information comprises information
associated with an unoccupied tile that is not explicitly specified in a
geo-query but for which the LBS or the client expects to be interested in
accessing information while occupying a different tile. Anticipated need
to know information, in accordance with an embodiment of the invention
may for example comprise information associated with an unoccupied tile
that a client is expected to occupy within a relatively short period of
time as a result of the client's motion.

[0033] In an embodiment of the invention, the client determines location,
size and/or spatial resolution of an occupied or unoccupied tile to
enable the information to be transmitted at a relatively small bandwidth
cost and relatively moderate use of client resources. Optionally, the LBS
determines, or contributes to determining, size and spatial resolution of
an occupied tile and/or an unoccupied tile.

[0034] For example, tile size and/or spatial resolution may be determined
by the client and/or the LBS responsive to a constraint, such as a cost
and/or a bandwidth constraint, determined in accordance with an expense
and/or bandwidth budget set to limit responses to geo-queries. By way of
another example, in response to a geo-query for locations of venues of a
given type that includes a client specification for a tile size, the LBS
may amend the specification and provide information for a larger than the
specified tile if the specified tile does not include a venue of the
given type or a sufficient number of the given type of venues. By
providing information for the larger tile, the LBS may reduce a number of
times the client accesses the LBS for the same information. In an
embodiment, the client and/or the LBS extrapolates motion of the client
to determine at least one tile that a client is expected to occupy and
provides anticipated need to know information responsive to the expected
occupancy.

[0035] The Tarry Time, component 50, of Response-ID 20 defines a period of
time for which the information provided by the LBS is considered to be of
sufficient relevance to remain stored in client memory. Depending upon
the type of information requested in a geo-query, Tarry Time may vary in
duration.

[0036] For example, a geo-query requesting wind conditions at a wind
surfing beach submitted to an LBS may be associated with a Tarry Time of
a few hours determined by a time period extending from a time at which
the geo-query is submitted to nightfall. On the other hand, a geo-query
for stores offering a sale on shoes may have a Tarry Time duration of a
week, during which shoe stores in a city hold a traditional sales week.

[0037] A Tarry Time data table 51 schematically shows options, for setting
Tarry Time duration in M (months), D (days), H (hours), M (minutes), and
S (seconds) for information provided by the LBS. By way of example, table
51 specifies a Tarry Time of 1 day. Tarry Time duration equal to zero,
that is all options M, D, H, M, and S, set to zero, determines that the
information is for a "onetime presentation" upon receipt, and precludes
the information being stored in client memory. A very large Tarry Time,
for example M=100, may cause the information to be stored until the
client deletes it.

[0038] In an embodiment of the invention, a client can actively determine
Tarry Time duration for information requested in a geo-query by
specifying the Tarry Time in the geo-query. Optionally, the LBS
determines Tarry Time duration. For example, a weather report provided by
the LBS for a city may automatically be assigned a default Tarry Time of
a day.

[0039] The Expiration Date, component 60, of Response-ID 20 defines a date
and time at which validity of information provided by the LBS to a given
geo-query for storage by a client is considered to expire and should be
revalidated to determine if it is currently accurate. The date and time
may optionally be defined by Y (year), M (month), D (day), and T(time) as
indicated in an exemplary table 61 shown in FIG. 1.

[0040] Expiration Date is different from Tarry Time 50. Information
provided by a LBS, in accordance with an embodiment of the invention
having an extended Tarry Time 50 duration may be subject to a number of
expiration dates during the Tarry Time period for which the information
is stored in the client's memory. For example, a woman vacationing in a
city may geo-query the LBS for visiting hours at art museums in the city.
The woman may have indicated in the geo-query, or in previous
communications with the LBS, that she will be in the city for a week, as
a result of which the LBS provided the museum information, identified
with an appropriate ETag, with a Tarry Time of a week. Optionally, the
LBS did not assign the Tarry Time to the information but the desired
Tarry Time was set and assigned to the ETagged information by the client
upon receipt of the museum information.

[0041] However, since museum opening hours change on a daily basis, the
LBS assigned the information an Expiration date as a date of a next
morning after provision of the information. Upon updating the information
the next morning, the LBS assigns the information a new ETag, and resets
the Expiration date for the next subsequent morning. The museum
information having a Tarry Time of a week is updated every day of the
week during the woman's stay in the city.

[0042] The Range, component 70, of Response-ID 20 provides a maximum
distance between a current location of the client and the location of a
tile identified by the Tile ID component of Response-ID 20 for which the
information in the tile is considered relevant. Information determined to
be irrelevant because it is "out of range" is deleted from client memory.

[0043] For example, assume the client is driving along a highway and sends
a geo-query for locations of rest areas to the LBS. The geo-query may
specify, or the LBS may determine that the information is to be provided
with a Range equal to a distance the client is expected to travel in
about twenty minutes. Then, if the client is driving at 60 kph
(kilometers per hour) the Range is equal to 20 km. As a result, the LBS
may provide the information for occupied tile sizes having a side length
of about 20 km. And upon leaving an occupied tile for which the rest area
information is provided, and traveling a distance 20 km away from the
tile, the information associated with the tile is deleted. It is noted by
way of example, for situations in which the LBS determines the Range, it
may do so responsive to past behavior of the client and/or statistical
behavior of travelers on the highway.

[0044] FIG. 2 schematically shows a geographical region 100 through which
a person (not shown), hereinafter also referred to as a "vacationer"
drives a car 102 from a start location "S" to vacation in a coastal
vacation village 104 bordering an ocean 106. Geographical region 100 is
overlaid by a grid 200 of nested, optionally BMTS geographic tiles 202
that are identified by Quadkeys. Some relatively large, low resolution
tiles 202 comprised in the grid are shown in FIG. 1. Tiles 202 have
borders indicted by dashed lines 204.

[0045] The vacationer driving car 102 is a client of an LBS 300. LBS 300
is schematically shown including a distributed network of servers 302
that communicate between themselves and clients of the LBS via the
internet 304 to provide clients of the LBS with responses to geo-queries.
Processors in the servers and/or the clients' mobile terminals, are
programmed with instruction sets that use Response-ID vector components,
in accordance with an embodiment of the invention, to provide the
clients' mobile terminals with the responses. During the trip to vacation
village 104 and during a stay in the village, LBS 300 responds to
geo-queries transmitted to the LBS by the vacationer with information
that the LBS transmits to the vacationer's mobile terminal (not shown).

[0046] Upon planning her trip, the vacationer transmitted a geo-query to
the LBS requesting a road map showing an advised route she should drive
to get to the vacation village. LBS 300 responded by transmitting a
response to her mobile terminal comprising information having a map 320
showing a major roadway 322 to be used. The response was associated with
a Response-ID 20 (FIG. 1) having an ETag labeling the information. The
map, hereinafter also referred to as an "overview map 320", showed
features in geographical region 100 at a level of detail provided by the
relatively large, low resolution tiles 202 schematically shown in FIG. 2,
in order to show all of roadway 322 from start S to vacation village 104.
Tile ID List 40 in Response-ID 20 (FIG. 1), listed Quadkeys of all tiles,
that is all large tiles 202 shown in FIG. 2, which the LBS used to
provide overview map 320 that displays roadway 322.

[0047] An LBS 300 instruction set, comprised in a server 302 and/or in the
vacationer's mobile terminal (not shown estimated that the trip from S to
vacation village 104 would last about three days and assigned a Tarry
Time to overview map 320 of four days to provide for a margin of error in
the estimated trip time. As various sections of roadway 322 and nearby
access roads (not shown) and associated traveler facilities were
undergoing repair that might result in changes to the roadway on a daily
basis during the person's trip, LBS 300 set an Expiration Date for
roadway map 320 to a date of a next day following a date at which the map
was transmitted to the vacationer. The Range component of Response-ID 20
is irrelevant for the overview map, since the map is meant to provide the
vacationer with a complete travel route independent of the vacationer's
location along the route.

[0048] On setting out at a time t0 from S to drive to vacation
village 104, the vacationer geo-queried LBS 300 for a local, detailed map
of roadway 322 and the roadway environs that designated locations for gas
stations, rest areas, restaurants, and motels along the roadway. In
response, rather than transmit information defining a detailed map
showing all of roadway 322, its environs and venues, LBS 300 transmitted
a relatively high spatial resolution local map to the person showing
features (not shown) for only a relatively small area 324 of geographical
region 100 that included a location of the person's car 102, which at
time t0 is in a neighborhood of S. The local map was defined by
information associated with relatively small, high spatial resolution
tiles 210 shown shaded.

[0049] The information defining the high resolution local map transmitted
to the vacationer by LBS 300 included a Response-ID 20 having an ETag,
and a Tile ID List listing Quadkeys of shaded tiles 210 that were used to
provide the map. At times subsequent to time t0, as the person drove
the car along roadway 322, LBS 300 updated the high resolution local map,
in accordance with an embodiment of the invention, responsive to
locations of the car determined by mobile telephone networks and/or GPS.

[0050] In accordance with an embodiment of the invention, Range 70 in
Response-ID 20 for the local map generated using information associated
with tiles 210 was defined as a function of direction responsive to
determination of need to know and anticipated need to know information.
The vacationer needed detailed information in a relatively small area
around a current location of the vacationer's car 102 and was anticipated
to need detailed information in a direction along a forward direction in
which the car was moving along roadway 322. For areas along roadway 322
behind the car, in a backward direction along roadway 322 opposite to the
car's direction of motion, detailed information was not expected to have
high relevance. Therefore, LBS 300 determined Range for the local map and
venue information it provided to comprise a "Forward Range" in a
direction along roadway 322 in which car 102 was moving, or if stationary
expected to move, longer than a Backward Range in a direction along
roadway 322 opposite to the direction in which the car was moving or
expected to move.

[0051] As a result geographical area 324 defined by tiles 210 extends from
a location of car 102 a greater number of tiles 210 and therefore longer
distance along roadway 322 in a direction towards vacation village 104
than in the opposite direction along the route. For tiles 210, Backward
Range 325 in a direction along roadway 322 away from village 104 is
optionally equal to about twice a diagonal length of the tiles and
Forward Range 327 is optionally about six diagonals in a direction along
the route towards vacation village 104. As car 102 moves along roadway
322 tiles behind the car move out of the Background Range and tiles along
roadway 322 in front of car 102 move into the Forward Range.

[0052] In accordance with an embodiment of the invention, Forward and
Backward Ranges 327 and 325 respectively, may be set to various distances
by the vacationer and/or LBS 300. For example, the vacationer may set the
Ranges responsive to a speed with which she might expect to travel along
roadway 322. She may expect to travel at an average speed of about 90 kph
(kilometers per hour) and set her Forward Range equal to about a half
hour of travel and her Backward Range equal to about a distance she might
travel in about 20 minutes. As a result, Backward Range 325 may be equal
to about 30 km and Forward Range 327 equal to about 45 km. Alternatively
LBS 300 may determine Forward and Backward Ranges 327 and 325 responsive
to statistics accumulated for drivers using roadway 322. Or the LBS might
set the Ranges responsive to real time speed with which the vacationer
travels along roadway 322 or responsive to past travel histories of the
vacationer.

[0053] In accordance with an embodiment of the invention, an instruction
set of LBS 300 optionally comprised in the mobile terminal of the
vacationer may check the location of car 102 at a frequency substantially
equal to a speed with which car 102 moves divided by a distance equal to
about a diagonal length of a tile 210. The LBS optionally determines the
car's speed from changes in the location of the car "reported" to the
LBS, divided by differences in time between reports. At each check of the
car's location, LBS 300 receives the ETag labeling the version of the map
in the vacationer's mobile terminal and determines which tiles 210 have
moved out of the Backward Range and which tiles have moved into the
Forward Range and updates the detailed local map of roadway 322 in the
neighborhood of car 102 along the roadway. Information associated with
tiles 210 that have moved out of range is deleted from the vacationer's
mobile terminal and information associated with tiles that have moved
into range relevant to features of the environs and venues geo-queried by
the vacationer is transmitted to the vacationer's mobile terminal. At
each update, the LBS resets the ETag that identifies the detailed local
map to a new, different ETag.

[0054] In an embodiment of the invention, each time the vacationer
operates her mobile terminal to access anew the local map after exiting
the map, the mobile terminal acquires the car's location and transmits
the location and local detailed map ETag to LBS 300. In response, the LBS
updates the loical detailed map as described above.

[0055] In accordance with an embodiment, the size and resolution of tiles
used to provide a detailed local map for the vacationer may change with
density of features and requested venues along roadway 322. For example,
in the afternoon of her first day of driving to vacation village 104 at a
time t1, car 102 is located at location L1 along a stretch of road
passing through a relatively sparsely settled area for which there are
few gas stations, rest areas, restaurants and motels per kilometer
distance along the route. As a result, for this stretch of road LBS 300
provides a detailed map at a resolution provided by optionally four
relatively large tiles 212.

[0056] It is noted that whereas all tiles used to provide a local map at
time t0 have a same size, and all tiles 212 used to provide a local
map at time t1 have a same size, information provided by LBS 300 at
a given time in response to a geo-query is not limited to information
associated with tiles having a same size. The information may be based on
tiles having different sizes. For example, when moving through a
geographic region with changing density of features and venues of
interest, LBS may at a given time provide information based on tiles
having different sizes and spatial resolutions.

[0057] During the morning of the second day of her trip, at a date and
time specified by Expiration Date 60 in Response-ID 20 (FIG. 1)
information provided by LBS 300 defining the overview map 320 was
scheduled to be checked to determine if it was up to date. At the
Expiration Date time, the vacationer's mobile terminal transmitted the
ETag in the overview map Response-ID to LBS 300. In the early morning
prior to the Expiration Date time, a section 326 of roadway 322,
schematically crossed out with an "X", was blocked to traffic so that it
could be repaved, and traffic was directed to a detour 328, indicated in
dashed lines, which bypassed section 326. As a result, LBS 300 assigned a
new ETag to information it had available for overview map 320. Upon
comparing the ETag received from the vacationer for the vacationer's
version of the overview map with the ETag that LBS 300 had for the
overview map, the LBS determined that the vacationer's version was out of
date.

[0058] In accordance with an embodiment of the invention, rather than
sending a complete updated version of overview map 320, the LBS
transmitted the new ETag for the overview map and information needed to
update the vacationer's version to agree with the LBS version. After
receiving the updating information the vacationer's mobile terminal
updated its version of the overview map and associated the updated map
with the new ETag.

[0059] Upon reaching vacation village 104, the vacationer submitted a
number of geo-queries including geo-queries for lists of theaters and
their playlists, seashore restaurants and bars, and beaches that allowed
windsurfing. Responses to the geo-queries were assigned respective ETags
and a Tarry Time of a week to match the intended stay of the vacationer
in the vacation village. Information providing the playlists was assigned
an Expiration Date one day in the future from the date of the geo-query
requesting the playlists and thereafter one day in the future from each
time at which the playlists were last validated.

[0060] All the information was provided based on information associated
with relatively small, high resolution tiles 214 along the village coast
of ocean 106, where feature density in the vacation village is relatively
high. For areas of vacation village 104 set back from the coast where
feature density is relatively low, the information in response to the
geo-queries was provided based on information associated with relatively
large low resolution tiles 216.

[0061] At the Tarry Time assigned information defining a last updated
detailed local map for a portion of roadway 322 ending at a geofence 330
marking entrance to vacation village 104, the detailed local map
information was deleted. And at the Tarry Time of four days from a time
at which the vacationer left starting region S, the overview map was
deleted from the vacationer's mobile terminal.

[0062] In the description and claims of the present application, each of
the verbs, "comprise" "include" and "have", and conjugates thereof, are
used to indicate that the object or objects of the verb are not
necessarily a complete listing of components, elements or parts of the
subject or subjects of the verb.

[0063] Descriptions of embodiments of the invention in the present
application are provided by way of example and are not intended to limit
the scope of the invention. The described embodiments comprise different
features, not all of which are required in all embodiments of the
invention. Some embodiments utilize only some of the features or possible
combinations of the features. Variations of embodiments of the invention
that are described, and embodiments of the invention comprising different
combinations of features noted in the described embodiments, will occur
to vacationers of the art. The scope of the invention is limited only by
the claims